Sugar reduction and associated biochemical changes in pomegranate (Punica granatum L.) fruit juice during non-alcoholic fermentation by Kluyveromyces marxianus.

The reduction of high fructose and glucose content without affecting other important biochemicals is a challenge for healthier pomegranate juice, which was attempted using non-alcoholic fermentation by Kluyveromyces marxianus (isolated from kefir grains). For optimization of sugar reduction, static fermentation was undertaken with varying temperature (20 to 37C), pH (3.5, 4.0), and duration (up to 21 days). The reduction of fructose, glucose and formation of ethanol was measured periodically using HPLC for 21 days. The maximum sugar reduction by 34% (glucose 42% and fructose 18%) without ethanol formation was observed on day 7 at 30 °C and pH 3.5 and insignificant change in organic acids. GC/MS analysis showed increase in esters content contributing to fruity aroma corroborating higher sensory scores. The metabolomics profiling of fresh and fermented juice using LC-MS/MS revealed enhancement in B vitamins including pantothenic acid (1.5-fold), and biotin (2.3-fold) during fermentation.